Apparatus for pressure cooking canned goods



- June 4, 1957 D. H. INGHRAM APPARATUS FOR PRESSURE qooxmc CANNED GOODS Filed May 26, 1955 .1... b t A A.

- INVENTOR. DUDLEY H. IIIGHRAH APPARATUS FOR PRESSURE COOKING CANNED GOODS Dudley H. Inghram, Omaha, Nebr.

Application May 26, 1955, Serial No. 511,177

Claims. (Cl. 99-366) The present invention relates to an apparatus for pressure cooking canned goods.

Heretofore in the pressure cooking of canned goods steam retorts have been used and it has been necessary to open and close the retort for charging and discharging goods in respect thereto. This has resulted not only in the loss of steam pressure which must be raised every time pressure is lost due to the opening of the retort, but has also resulted in the loss of time and has proven to be a costly type of operation. Additionally it has been found to be difiicult to maintain in the retort like or uniform pressures during each individual cooking operation with the consequent result that one batch of canned goods may be overcooked and a subsequent batch under or insurhciently cooked.

The present apparatus has as its primary object the provision of an arrangement wherein there is a continuous flow of the canned goods through the cooker to thus overcome the shortcomings of prior devices and to provide an arrangement having great capacity due to the uninterrupted flow of the cans through the cooker, and to assure a continuous and uniform cooking temperature and to obviate the necessity of repeated handling of the goods with the consequent material reduction in the cost of the cooking operation.

Another object and advantage of the invention is the provision of an arrangement where the relation between pressure and temperature in the cooking tank is overcome. This is highly desirable when it is considered that in order to reach in a pressure tank a temperature of 230 F. approximately 40 pounds of steam pressure is necessary. Any pressure greater than 7 pounds could result in crushing or damaging the cans containing the goods. Heretofore in order to reach the necessary cooking temperatures yet avoid raising the pressure in the retort above the point where damage to the cans would result, steam was allowed to escape continously from the retort. This resulted in tremendous wastage of steam which is costly to produce. In the present improved apparatus the pressure within the cooking chamber or vat of the cooker is maintained in a novel yet simple manner and this pressure may be conveniently varied at will.

Another object of the invention therefore is the provision of a novel arrangement of selectively maintaining and selectively varying the pressure within the cooking chamber of the cooker.

Another object of the invention is the provision of a cooling means for cooling the cooked canned goods and to make the cooling operation a continuous part of. the entire operation and to continuously transfer the cooked canned goods from the cooking chamber to the cooling chamber without causing a reduction or" temperature and pressure within the cooking chamber.

Other objects and advantages of the invention will be apparent to those skilled in the art and will be undertates Paten H extends lengthwise of the cooling chamber.

stood from the following description when read in the light of the accompanying drawings.

In the drawings:

Fig. 1 is a view partly in section and partly in elevation and to some degree diagrammatic in nature of an apparatus for practicing the improved method.

Fig. 2 is a fragmentary enlarged view in vertical section illustrating the connection between a pair of standpipe sections.

The apparatus comprises a pair of spaced-apart horizontally disposed tanks one of which is a cooking tank A and the other a cooling tank B. These tanks are interconnected by an air lock C the precise purpose of which will be hereinafter described.

At its inlet end 1 the cooking tank is in communication with a stand-pipe made up of a plurality of sections 2, 3, 4 and 5 while the outlet end 6 of the cooling chamher is in communication with a stand-pipe made up of a plurality of sections 7, 8, 9 and 10.

The uppermost stand-pipe section 5 has its upper end enlarged to form a tank D and the upper section 10 of the other stand-pipe is enlarged to form a tank B.

As will be hereinafter described the cooking chamber A and its stand-pipe are filled with a liquid and the cooling chamber B and its stand-pipe are also filled with a liquid. A steam carrying pipe or pipes 11 are disposed in the cooking chamber and are supplied with steam from some suitable source of supply, not shown. A refrigerant coil or coils 12 are disposed in the cooling chamber and are connected to any suitable type of refrigerant apparatus, not shown.

An endless type conveyor F is horizontally disposed within and extends lengthwise of the cooking chamber and an endless type horizontally disposed conveyor G A vertically inclined endless type conveyor H extends upwardly from the delivery end of the conveyor F and terminates in the air lock or air chamber C at a point above the reception end of the conveyor G.

A tank I containing compressed air provided from any suitable source, not shown, has an outlet pipe 13 adapted for communication with the interior 14 of the air look. A normally closed valve 15 is in the air line 13 and is operated by a float 16 disposed within the air lock chamber on the surface of the cooking fluid K.

The cooking fluid or solution is water, but it could be any other liquid of substantially the same specific gravity as Water with a boiling point in the neighborhood of 300 F.

The cooking fluid or solution completely fills the cooking tank and the stand-pipe thereof. It will appear later that as cans are conveyed to and deposited in the cooking chamber stand-pipe these will displace water and to maintain the proper water level, which is indicated at 17 at the top of the stand-pipe and at 18 within the air lock, this displaced water is permitted to overflow the upper edge 19 of the uppermost stand-pipe section 5 and flow into the overflow tank L.

A supply of water for the cooking side or system of the device is maintained in the tank M. A flexible pipe 20 interconnects this reservoir and the tank L through a pump 21 and a second pipe 22 at the bottom of the overflow tank. The pump 21 will return the overflow fluid to the reservoir. A third pipe -3 delivers Water from the reservoir to the upper end of the uppermost stand-pipe section 5. This pipe intermediate its length is provided with a normally closed valve 24 which is moved to open and closed positions by a float operator 25.

The cooking end of the apparatus is the receiving end and filled and sealed cans are suitably delivered to a reception tank N having therein a liquid 26 of high specific gravity within which the cans will float. There is an endless type conveyor having thereon a plurality of pusher blades 27 which pass over and extend slightly down into'the fluid 26 within: the receptiomtanlc 'lf his conveyor operates to engagercansfloating in the: tankand pushes them up the inclined ramp 2& thereof and dumps-them in the water K at the upper end of the cooker chamber stand-pipe-sectionS.

The cooling: chamber and the entire associatedand communicating. stand-pipe are filled with a cooling solutiomhaving a high specific: gravity andone' sulficiently high so the filled cans will float therein. This cooling liquid or solution is designated as an entirety by P and itslevel. within the-airlockis indicatedat. 29 and within thetank-Eat 30.-

The levels of this fluid will. vary in: accordance with the number of cans travellingihroughihecooling side of thev mechanism and accordingly: provision for handling:overfiow fluid-and supplyingadditienal fluid is provided.-

There isan. overflow tank-v Q and. asupply tank or reservoir R. The bottom of. the overflow tank is con-- nected with the reservoir-through-the-pipes 31 and 32 in which a pump 33 isdisposed. Liquid is replenished to this side of the system from the tank to. the tank P throughthe flexible. pipe- 34 having' inits lengtha normally closed valve 35 which isoperable to openand closed positions by the float 3&

An endless type conveyor. similar tothe conveyor (1 describ'edis associatedwith the'tank B Thisconveyor'S is provided with aplurality of pusher blades 37 to travel; over arid-in the surface of the fluidwithinthe pipe P and engage the floating cans and. pushes them up the inclined ramp 38 where they are delivered to any suitable con veyor. system which illitakethem to what is known as the case 0 room of the packing plant; 7

An. insulated barrier or danrT'extends across the air lock chamber beneaththe conveyor H andpreveuts the coolingfluid from reaching-the cookingcharnberr The fluids are. also prevented from joining by reasonof the air pressure which is maintained in the air lock. The degree of this air pressure will be referred to-hereiuafter.

The degreeof pressure and its maintenancewithinthe system and the manner in whichit-may. bevaried'will now be described. For every two feet-of heightof-liquidg inv the. stand-pipes there is approximately one pound of pressure. The: stand-pipes accordingly are" made of the proper length to provide theproper pressure within the lower chambers. Once the. stand-pipes are made of the proper heights no alteration or change-is necessary where a single product is to he processed Where difierent pressures are desired or necessary it is intended toadd or remove intermediate stand pipe sections; For this reason a simple yet elhcientjoint is provided between the abutting ends of. sections. In Fig.1 the upper-endof section 3 and the lowerend of section-4 areillustrated. Here itwill be seen: that section? is .provided atits-upper end with a groove 39 having in its bottom a packingflfl; The lower. end of the pipe section 4 is providedwith'acircumferential tongue 41 whichextendsinto the grooveand rests upon the packing. As- Willhereinafter appear, there .is always weight-upon these sectionsandithasbeen found" that the joint described is adequate to prevent leakage.

By reason of the adjustability' ofl-the heights of thestand-pipes it is necessary to provide meansforraising andlowering. the loading and unloading. facilities. or. mechanisms of the system. This could be done in many ways other than that illustrated and now to bedscribedI The device illustrated for raising and lowering the loading facilities of' the device comprises a" platform V and a pair. of'hydraulic lifts ea'ch embodying a lift'cylinder45and '46. At one end the platform is providedwith an end wall 48 upon which the top 49 of the overflow tank' rests.

No illustration is made of the mechanism for operating the hydraulic lifts as such devices are well known and understood and are commonly used. One place where lifts of this kind are in common use is in service stations for raising automobilesi for lubricating jobs.

A cylinder lift is providedfor the unloading facilities of the device; In this instance"theplatform is 51 and the hydraulic lift pistons o'r"cylinders are 52 and 53. An end wall 54 of the platform supports" one-end 55 of the overflow tank top while an elevated or raised portion 56 of the platform is beneath the opposite end 57- of the tank top.

It will be seen that through proper positioning of the elevating means a portion of the Weights of the loading and unloading mechanisms can be placed upon the upper stand-pipe sections 5 and 10. with: the result that the section interconnections, illustrated in Fig.2, i are rendered liquid-tightdue to theengagementunder pressure of the tongue. of I one section withathe packing in thegroove of the other section V The commune in the coolingend of the mechanism is one whichis ofisufficiently high. specific gravity: that the loaded andlsealedicans will float therein. There are numerous such. fluids, one ofwhich isa concentrated solution of calcium. chloride.

The purpose of. the air: lock Crinadditionto providing an apparatus through .whiehithe-canscanbecontinu! ously progressed without the=lossofpressure in-the-cooking section of the device,. is. to maintainthe pressures cohstant'in both the cooking and coolingsections: ofthe apparatus and to maintain theliquids at the proper level. The pressure within the air lock willbe maintained at. the same pressure exerted upon the fluidsin thechambers- A and'B'by the fluids in the two standpipes. If the pressure brought about'by the pressure in the stand-pipes is seven ounds-per squareinch, that willbe the pressure maintained inthe air reservoir I; However, the maintenance of the proper pressure in the air lock could be accomplished by means of "a pressure controlvalvein theair' line 13 should it be so desired. Such a regulator would be set for the proper air pressure. which should bemainta'ined inthe'airlock.

Obviouslyth'e' air or gas pressure in the air lock will: maintain the fluidsat-their properlevels and prevent thenr overflowing orfillingl the air lock. The pressure in theair lo'ck accordingly'constitiites a dam or: barrier which prevents the cooking fluidfi'om reaching andcomingling with the coolant fluid;

There is"n'oillust'ration of the drivemeans for any of.

the" endless" conveyors. It is intended that there be speed: regulators'forthe drive means of these conveyors but Inasmuch as speed regulators for conveyors are old and wellknown, illustration" of them" is considered u'nneces saryt There are many speed regulatedconveyors on the market-andthe one most suited-to the present apparatus would-be selected;

Having; described an apparatus by which the present improvedmethod can be practiced, a short descriptionof the operation of the apparatus will now be given.

The method: is intendedfor use-on large scale: operationsinwhich cans maybefilled and sealed-atthe rate ofas high as eight to ten thousandcans per hour. The capacity of the present device is not limited as enlatggement of the overall size of theparts makingnip the. apparatusf would result in increasing. its capacity, as. will bereadily apparent.

The presentmethod might well be called asink and floa't method'in that the cans are permittedto sink into the cooker portion of the apparatus'and float outwardly. from the cooler portion 'of the apparatus. The feed to the device is or can be continuous :and reduces to the the manual labor incidennto a pressure cooker for canned goods.

The filled and sealed cans are suitably brought to and dumped into the liquid within the reception tank 26 in which they will float. The cans are pushed from this tank by the conveyor into the enlarged upper end D of the stand-pipe section 5. Water within this standpipe and also the cooking chamber at the lower end thereof is maintained, by the heating pipes or elements 11, at the proper temperature to properly cook the contents of the cans.

Immediately upon entering the upper end D of the standpipe section the cans sink to the bottom onto the conveyor F in the cooking chamber. Here the water is at the proper temperature and is maintained at the desired pressure by making the stand-pipe of the proper predetermined height. The pressure within this chamber can be varied by inserting or removing stand-pipe sections.

At this point it might be pointed out that the stand pipe for the cooking chamber could be disposed at an inclination to the vertical if it were found that the cans sink so rapidly downwardly through the stand-pipe as to injure them when they reached the bottom and contact the conveyor.

Upon reaching the conveyor F the cans are conveyed through the cooking solution within the cooking chamber A. Through proper setting of the speed regulator the cans will be caused to remain in the cooking solution the proper length of time to be properly cooked.

As the cans enter the stand-pipe and leave the cooking chamber the level of the liquid will be caused to rise and fall which would vary the pressure at the bottom of the stand-pipe, that is, within the cooking chamber. To prevent this variation in pressure the hereinbefore described manner of permitting an overflow of water from the top stand-pipe section 5 is provided. Should more cans be leaving the cooking chamber than are entering, the level of the liquid would fall and this would result in the actuation of the float valve 25 to cause the liquid level to be immediately brought back to the proper level.

When the cans reach the end of the conveyor F they fall upon the conveyor H and are carried through the air lock C and are dropped off into the coolant fluid 29 within the cooling portion of the apparatus. As pointed out, this coolant fluid has a specific gravity such that the cans will float therein. The cans accordingly remain above the conveyor B and are carried or pushed by that conveyor to the lower end 6 of the stand-pipe made up of the sections 7 to 10 inclusively. The adjustment on the speed regulator drive of this conveyor is made such that the cans will remain in the chamber B the proper length of time to be adequately cooled.

Immediately the cans reach the lower end of the standpipe they float upwardly into the discharge tank P and float up against the conveyor S by which they are pushed up the ramp 38 for discharge to proper conveying means which will carry them to the case ott room of the establishment.

The liquid level can change in the cooling portion of the apparatus by variance in the delivery of cans into this section of the device and in the delivery of the cans from the discharge tank. It will be understood that the liquid of the coolant is maintained through provision for overflow into the overflow tank Q and the delivery of additional fluid under the control of the float valve 36.

Most canned products have almost neutral buoyancy in water. Where the buoyancy of the filled cans is such that they will float in water a slightly different arrangement is necessary, as will be hereinafter described.

Inasmuch as it takes a greater length of time to perform the cooking operation than the cooling operation there should be no crowding or jamming up of cans in the cooling side of the apparatus. In any event proper adjustments of the several conveyors will assure proper and continuous flow of cans through the apparatus.

The apparatus has the particular desirable attribute that it will handle cans of any size or shape'without alteration of the mechanism. Actually cans of diiferent sizes and shapes can be processed at the same time provided the cooking periods for the contents of the cans is the same or substantially the same. This is a particularly desirable attribute as where changes or alterations are necessary for handling cans of difierent sizes and shapes a great deal of time is lost which increases materially the cooking operation.

Departures from the specific mechanical arrangements shown and described can be made without departing from the inventive concept. Where the nature of the canned goods is such that the cans depart from neutral buoyancy in water, such as for instance shoe-string potatoes, cans of this material would have to be conveyed through the apparatus in covered baskets. To provide for this would not be diflicult. The conveyors F, G'and H would be eliminated and a continuous conveyor extending from the upper stand-pipe section 5 through the cooking chamber, air lock, cooling chamber and upwardly out of the standpipe for the cooling chamber would be provided. The baskets would be suitably secured to this conveyor and carried through the machine by the conveyor element.

The fluid in the can reception tank N and in the coolant s1de of the apparatus is identical and hence any can which will not float in the coolant liquid will not float in the reception tank liquid and would therefor not be delivered to the cooker chamber.

The apparatus illustrated and described is to be considered illustrative of the inventive concept and not limitative thereof. If space is an important consideration space could be saved by inclining the two stand pipes toward one another. Additionally by the use of proper conveyors and proper shaping of the air lock the coolant chamber could be positioned to parallel the cooking chamber.

What I claim is:

l. A device for continuously processing canned products comprising, a pair of spaced apart horizontally disposed chambers, an air lock providing communication between adjacent ends of the chambers, one chamber being a cooking and the other a cooling chamber, a stand-pipe communicating with the cooking chamber, a second stand-pipe communicating with the cooling chamber, a liquid having a specific gravity such that the cans Will sink therethrough filling the cooking chamber and its stand-pipe, means for heating said liquid to a cooking temperature, a liquid having a specific gravity such that the cans will float therein filling the cooling chamber and its stand-pipe, means to chill the liquid in the cooling chamber, means delivering a fluid under pressure to the air lock and maintaining therein a pressure equal to that exerted by the weight of the liquids in the stand-pipes, means to deliver cans to the cooking chamber stand-pipe, means to progress cans through the cooking chamber towards the air lock, means to progress cans through the air lock to the cooling chamber, means to progress cans through the cooling chamber to its communicating stand-pipe, and means to remove cans from the upper end of said stand-pipe.

2. A construction as defined in claim 1 wherein, the stand-pipes are made up of a plurality of insertable and removable sections, whereby the stand-pipes can be lengthened or widened to vary the fluid pressure existing in the cooking chamber and the chilling chamber.

3. A construction as defined in claim 1 wherein, means is provided for maintaining the liquid levels constant in the stand-pipes irrespective of the number of cans in the stand-pipes and in the cooking and chilling chambers.

4. A construction as defined in claim 1 wherein, a power driven conveyor constitutes the means for progressing the cans through the cooking chamber towards the air lock, a power driven conveyor constitutes the means for progressing the cans through the air lock to the cooling chamber, and a power driven conveyor constitutes the A calm-action 'zis defihe'd iii claim I- wiiereiir; a" owerdriven conveyorconstitutesthe meansfor progress ing the ca'ns throt1gh the cooking chamber towards the'a'ir lock-, a powi driven: conveyor constitutes the means for rogressingthe: cans through the=air1ocl to the cooling chamber; a power driven conveyorconstitiite's thbfirean's for progressing the cans through the cooling chamberto' its co'zaminunicating st51jd pipe; an'dspeed regulator means for each conveyor tb progressthe cans at'the proper speed to as sure p'r'op' er cooking a'n'el chilling o'f'the cans; I

62 A-constiiictioiiasdefined in claiim 1 wherein; there" speeifiti such thait the cans fio'at therein, a conveyor for movin the' cans from said tankintcv the" liquid: sfithezup' er 61121505 said last named Mand i e; a delivery tank communicating with the upper" end of the; chhling chamber 'stsnd ipe and filledwith a-liquia hav inga s ecifie ravity such' thlait th'ejc ans willfldat' therein; and mechanical rneans for removing the cans from said tank;

7. A constr-nction'suchas defined in claim 1 wherein, means is provided: for raising and loweringthe means which deliver the cans -to the co'oking" chamber sta'n'cl pipe and' the mezms whicliremove'thecans=fron1-the upper end" of the chillling chamber stand-pipe.

8'. A-constrnction such asdefined' in clizim 1 wherein, there is associatedwith the" upper e'nd of the cooking chamber stand-pipe a tank for the'receptiom of overflow the cooking chamh'ersta'nd pipe is disposed at-ariinclin'aand ins'eflr'tahle sections; means for reising andi loweriiz'g' the cans? delivery M68118: of the; cooking chamber stani i -i pipe and the means which removes the cans fromthe upper end of the chilling" chzfmbe'r stnd-pip'e; and said raising ahd'lowering m'eans perrhitting 21 portion of the weight'of said candeiivery and=removal means to rest up'onthe; stand -pipe-wifli which each is respectively as=- nere enees citedimthefile-of this patent STATES 'F l y PEN TS l709481 Mullen Apr; 16; 1919 2,472,970 Han na Iime 14; 1949 2,56%645' Viall Octi 2, 1951 25649589 Flynn A1.1g'.'-18 1953 2-,695}5F$ Camus- Nov; 30; 1954' 

